I paid 27k for a '09 1531 w/loader and backhoe. Does this 1528 have a loader also? If so, I'd say 17.5k is a steal. Before I bought my 1531, there was a used 1528 TLB for sale at 22k, I don't recall the hours but I believe it was an '07 hydro.
If it's clean, with only 160 hours it's barely used, I'd jump on it.