As stated above, check out Tripadvisor reviews to see what people have thought. Also check out the bed bug registry sites to see if there has been any recent problems. I've stayed in Kissimmee a lot and find at that price, the place is either a dive with paper thin walls or it's quite a drive from the parks. So you spend a lot on gas and sitting in traffic wishing you were having fun.
If you look on Tripadvisor under Vacation rentals, you can input your search criteria (price, size, location) and you might find something awesome at a great price. I booked an entire condo in west Kissimmee for $70 per night. It was 2 bedroom, complete kitchen and a short walk to the big pool. Where ever you choose, make sure you check the hotel room yourself (without baggage) for foul smells and bed bugs.