We owned the 2002 version of that coach for 8 years and it served us well. It had 90k miles when we traded it in 2013 and the new owner is still using it.
126K miles is no issue if the coach has had its recommend service. You can pull an engine oil and trans fluid samples for analysis. At 15 years old some of the house systems may be needing replacement......fridge, etc. All of these things need a lot of care and fixing so just go into it eyes wide open.
Check it thoroughly for any evidence of water leaks from roof, windows, etc.
'07 Country Coach Allure 470 Siskiyou Summit #31578, Cummins ISL 425; 2014 Ford F150 toad; Air Force One Toad Brake.
Glen Allen, VA; Smith Mountain Lake, VA.