I suppose everything has a price. lol
If I had a $3000 mower I might be more reluctant but then again, the equipment would be tougher.
I have turned down really bad ones, because my equipment cannot handle it; the other ones I charge more for, but sometimes I think not enough so make sure you don't underestimate if you decided to do it.
My disclaimer if I do it:
"It's not going to look that great the first time"
I tell them because I have to mow it higher and I use mulching mowers so it won't mulch everything. I'm not going to rake stuff up, if it doesn't mulch.
If it's so high it's going to keep killing the engine then I'm not going to do it or maybe if I get a side discharge mower, but I'll tell them there's going to be clippings. Reason I don't have a side-discharge is those aren't my normal type of jobs. Many of them are just one cut and if they aren't they probably let it go too long in between mows, so it's your call, depending on how much business you have: If you have plenty of business I would say it's not worth it.
LawnBoy push mower
Echo SRM 225
Hitachi Handheld blower
'99 Ford Ranger XLT