The rear sway bar bushings are not expensive themselves, and with a jack, jackstands, and a few basic tools, aren't hard to replace, either. One of the easiest repairs to DIY, actually, in terms of suspension stuff.
Are they trying to charge you $251 to change a hi-beam light bulb? If so, run. And then change it yourself ($6-$10 for the bulb, 5 minutes to change it).
Oil pan gasket should be changed but as long as its not leaking a lot of oil onto your driveway, etc... then I'd leave it for a bit until you find a mechanic you trust (ie: not the stealership)