$225 may not be unreasonable . Installing a new part may be easy , but finding the problem and verifying it may not be . I have a little trouble with his $220 minimum charge , most shops minimum is $40 or $50 bucks , was this a service call , ( came to your house ) . Many shops get recommended because the quality of work is good , rather than the price .

I once had to pay an HP tech to come to my home ($75) for gear under warranty and he could not fix it...

But, if he told you in advance what his minimum is and you agreed then it's totally reasonable.