This Place Isn't Bad At All - Other Reviews Are Bull
These other reviews are ridiculous. They are so exaggerated, I don't trust the majority of them. I'm staying at the Dollar Inn in Greenfield, IN right now, and to sum it up, I'd say it's "old but clean." They do advertise $29.99 HOWEVER on Friday & Saturday nights (weekend) they charge $34.99, which is what I'm paying now since it's a Saturday night. In any case, the room is perfectly clean, the beds are comfortable, and the a/c works fine. They also have free WIFI and that's really the only thing I had an issue with. I stayed last night (Friday) as well, and had practically no internet. When I went to the office today to extend my stay another night, I mentioned the WIFI issue, and they gladly relocated my room to another end of the building where the WIFI signal is very strong. 
They are very accommodating, nice people, and you get more than what you expect at $30/night. I'm a transporter, so I stay in a variety of cheap hotels ALL the time. This is the cheapest hotel I've ever stayed in so far, and is WORLDS better than the other hotels I've stayed at for $10 more per night. If you go into it expecting a Hampton Inn, you're going to be disappointed. If you go into it expecting to get a $30/night hotel room, you'll be pleased to see it's more like the $40+ rooms at other hotels. 
I highly recommend this hotel to those looking for a clean, decent place to stay for an incredibly low price.