Lower Unit rebuild

my reverse isn't working. took lower unit to a shop. they initally told me that it was an easy job and that it would cast a couple hundred. after they took it apart they say it needs a new reverse gear and clutch dog, and parts and labor is going to be about 650$. i cant swing that just for reverse so i have to pay them 50$ for looking at it, which is lame cause they told me it would be a couple hundred which i would have paid. anyway, does that seem like too much? i see rebuilt LU online going for 550$. what year and hp LU's will work for a 1988 90 ETLG? thanks.

[boats.net]

The rebuilt lower units are often cheaper than the cost to repair them. I know the 1984-1990 are same lower unit.

thanks. what hp range will match my 90?

[boats.net]

The C85 and 90