The powerbook 1xx power adapters/chargers use the same style and sized plug as the portable, so that part isn't a problem. The problem is with getting a power adapter of the correct rating. Due to the way the charging/power circuit is designed, using an AC adapter/charger of ANY amperage higher than the original specs will put the logic board at risk for further damage, even if the caps on the board are replaced.

Don't ever forget --- never power a mac portable with an adapter of any higher rating than the original! This is the #1 rule of thumb when working with the Portable.

As for the price, it depends on what it comes with, for that price. Does it have the bag, main battery, or anything else? $150 for a portable, when comparing to eBay prices, sounds like a great deal. But when it comes to realistic value, it sounds a little steep, being in unknown working condition.

99.99% positive that the board needs new capacitors. I wouldn't mess with powering it or anything else until the board has been cleaned and re-capped to remove any electrolytic capacitor goo. That stuff will eat away at the traces, vias, and surface mount pads. If the board has been with leaking caps for a long time, chances are you have a lot of rot going on and it will take some work to get going again.

If it has been powered by the wrong adapter in the past, several parts of the circuit are probably toast as well.