I have some personal experience in this, having been in a very similar position. The caveat in my case is that I knew I was going to have to move the machine from 1 location to another and basically once you pass the magic 25 999lb combined weight one needs a CDL (especially if moving across state lines).
So I was looking for a machine that I could move and be no more than 12k including trailer. I ended up looking at the Bobcat labeled machines that were made by Earthforze in the Czech republic. The factory got closed after the acquisition by IR and so commercial operators dumped them as fast as possible because the Bobcat support is lousy. Of course that was years ago, and the machines have been well picked over by now.
The one I got is a Bobcat B200. It has a 30hp 3 cylinder Kubota turbo diesel, a hydrostatic transmission with 4 equal sized tires and permanent 4wd. For me the equal sized tires was important along with 4wd, otherwise the 2wd or small front wheels can be limiting very fast when trying to move 3/4 yard of dirt or gravel in the bucket and 2 undriven little wheels up front.
I will say this: Plan to do absolutely every bit of maintenance on this type of machine yourself. If I did not, I would be many thousands of $ in the hole.
I have replaced many hydraulic hoses. Chasing down where to get the right crimp fittings and the right hose can be a chore but once you have it figured out, keep a bunch of fittings and hose in stock, then getting a replacement hose is as simple as driving down to the local hydraulic store with hose and fittings and coming back a few hours later. I keep a laminated card for the crimp dimensions for all the hose sizes, and you need it else the hydraulic shop will not guarantee their work. The electrical system on my machine is relatively simple, but it has given me fits anyway since there is an e-stop system, an electronic lift pump for the fuel, the usual fuel shutoff valve, glow plug circuit, neutral interlock for starting and some lights. I have replaced the alternator already 1 time (it was dead) and still have intermittent issues with the charge light coming on. Sometimes it won't start or it will start then die.
My machine was a 2003 model which I bought in 2009 during the financial crisis for $12k with 1300 hours on the meter. I assume it had been a rental machine, since the loader bucket had all its paint on, but the hoe was about shot and all the pins on it were loose and anything the bucket teeth could reach when digging was mangled. Last year I replaced all of the hoses on the hoe, and this year I am starting to replace all the pins. I did an oil change before the last winter that was a bad idea, since it turned out the oil was clean and on top of that I refilled it with the wrong viscosity of oil. W20 instead of W45 (I used general purpose hydrostatic transmission oil and in fact this model uses engine oil). Since the oil viscosity was too low, the pump could not make system pressure and it was as if the machine decided to start on a "go slow" strike.
Despite the generally "tough" appearance of these construction machines, they can be damaged much more easily than one may think. Last year while pushing over brush, I made the mistake of driving over a hardwood sapling with a stem about 3/4" in diameter. It just so happened that the stem found the perfect angle to get into the radiator fan and deflect it (it was a plastic fan) so that the blades of the fan cut through the 1st row of radiator core tubes... I had to dismantle most of the front end of the machine to get the radiator out (bad design by the guys in the Czech republic) including removing both front wheels to get to fasteners and I had to do this out in the field right at the edge of a swamp. Then find a shop to re-core the radiator, then go back and put it all back together again. Such a simple thing and $500 out of my pocket (would probably have been a $1500-$2000 repair if I had taken it to Bobcat).
Similarly, on the same farm (not mine) the owner went to tear out a few fruit trees and got it well dug into some soft ground. in so doing, he managed to pull the electrical harness off the lift pump by virtue of some tree roots that were sticking out the ground, upon which the machine quit and again we had to repair it in situ (we had no suitable machine to recover it from the situation it was in while not running (there was water over 12" deep in the hole).
So basically, consider how you will move it if you need to. Do you have a friend who has a CDL and a trailer, or will you be hiring that out every time ? Will you be capable of repairing everything and figuring out "who's stuff" your machine has in it in the way of hoses, fittings, valves etc ? Are you ready to fix the machine in any situation you manage to get it into ? Best to think about that before you get yourself in any situations...
Look carefully at the tires. A set of tires on my machine will cost close to or more than an engine replacement. They will probably also go at nearly the same time. I rejected some slightly bigger machines with better features because they needed new tires immediately and that could easily have run me $3000+.
