oh, the fact that you wanted to "rent" made me think you didn't own a machine (the usual person dealers rent them to: is persons who don't own one, trying to find something they lost). Then you're going to have a hard time finding a dealer who specifically has a 250 rent. I mean, even if you had a Garrett dealer in your town, there's no guarantee that he'd be renting the 250, as opposed to any other number of Garretts over the years that've been made. By comparison, the Whites dealer in my town just happens to have an old 6000d series 3 as their rental. But needless to say, Whites has had dozens of models over the years, so for someone to come in and specifically say "I want to rent an MXT" or "Classic 3" or "Eagle", etc... the store owner would probably look at them with glazed eyes and offer to rent them their single rental model: a 6000d series 3.
You're best bet is to borrow one for the day from someone in the area. Maybe state specific forums would lead to connections of whomever owns one in your area. Some of the Whites lower end units mimick the abilities of the 250, so don't discount a Whites as just as good a turn-&-go machine as the 250. Like the prism, classics, etc... The sounds and quirks all vary, but in my personal opinion, the 250 is a very over-rated machine. I've hunted side-by-side with one, and they don't go deep, and don't have good target separation, TID, etc.... JMHO.