Ask yourself the following:
1. Am I likely to use this in a game more than twice?
2. How much would I pay for an unassembled resin kit of the same thing?
3. Have I paid my gas and electric bills for the month?
And since it was a flea market, I'd offer $5 for it and pay up to $10. Underscale is slightly better than overscale, particularly for something like this, which is more a bit of scenery in most mini games.