Trying to figure out what offer to make for this trimmer mower

[Frank]

The widow next door has a trimmer mower (like the DR trimmer mower, but some other brand). Its pretty old looking, wheels wobble a little, missing the guard and a little damage to the engine cover, but starts on the 1st or 2nd pull. I borrowed it today and was amazed how great it worked around the pond. Sure beats a handheld gas trimmer. I can't find any for sale to make any comparisons to offer her a fair price. She is trusting me to be fair with an offer. I am thinking $100 - 150 maybe given its condition.

Any ideas? Have you seen any used?

[Forever_frost]

My grandfather bought a DR for 500 so I'd go 1-2 if you like it. Hell, I'd pick one up for 100

[KCHAR]

100 max