Judging from the signs around Mostar, Villa Mostar is one of the more expensive pansions in the town (we paid 42 Euro for a double). However, even with nothing to compare it against, I think the price is more than reasonable.
It's spotlessly clean, and our room was quite spacious (it actually had an extra single bed). Guests get access to the back garden, which overlooks the river. There's also a computer, with (relatively slow) Internet access, that you can use free of charge, and the owner tells us there will be Wi-Fi in the next few months.
The owner (and his wife) is very friendly, speaks excellent English, and is very honest about the town and what there is to do and see there.
There's a mosque nearby, but that didn't cause us any issues with sleeping.
A tip on finding Villa Mostar. Heading east over the Titov Most (Bridge), take the first right and walk about 200 meters, and look for a red sign.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC