The 5425 pricing is higher than the 5420 pricing for starters. Secondly I went and priced a 5425 and you would have had to have gotten every option available to get up to $39,266. The base price of that machine starts at like $31,000 with mfwd. If you want a used 5420 I looked in the paper today and there are 15 within 50 miles of me with a loader from 24k-32k. A TN 75A is a nice tractor and nothing wrong with it but the pricing on the deere is VERY inflated. And maybe the dealers in your area are that inflated.
If you go off of retail from deere's website the list price of a 5425 equipped similiar to a TN75A is $35,171. The loader list price is $5106 not $6k. That's a total fo $41,277. Take your 20% off of list and you are at 33,021. I can get 23-25% off of list so my cost would be a little lower. The 5420's are even lower than this. Still makes the TN lower priced.
BUT if you are comparing a 5425 to a TN 75 you are not comparing apples to apples. The 5425 is a FOUR cylinder 276 cu. in. motor compared to a 3 cylinder 179 cu. inch motor. BIG price diff. and especially torque #'s going from a 3 cylinder to a four cylinder. Also you are getting a 62 pto hp motor compared to a 65 pto hp. Regular hp is 81 compared to 72. In the TN you'd have to jump up to the next size tractor to get that hp. You get a wet clutch compared to the dry clutch in the TN. A wet clutch will outlast and outperform a dry clutch by a long ways. That is a huge difference right there that you are getting. Another real kicker is pump flow. You get 25 gpm with the Deere and only 16.9 gpm on the TN. For loader work and doing rear hydraulic work that is not even comparible. And then there's little things like only being able to add 4 valves on the TN. Deere you can go 6 valves. Optional equipment like electrical for implements and block heater is optional on the TN and standard for the Deere. That's a $380 difference.
Anyway enjoy the TN that is a nice tractor as well that should give you many years of great work. But there is a reason that the Deere is higher and it's not just for green paint.