$300 is a steal for a .380. I paid $359 for mine and I like it very much, would do it again even if it were a little higher in price, but not over $400.
If at all possible, shoot one first since some folks find it very harsh and painful. I don't find it punishing at all, so I think hand structure makes a big difference in how it feels. I know shooting one is going to be difficult since there aren't a lot out there and probably no range carries one for rent.
They are also heavier than a Guardian .32, so if you find a .32 to shoot, don't think you now know how the .380 will feel, they are, for all comparison purposes, completely different guns.
Do a search on "Guardian .380" (with and without the decimal point) here in Autopistols and you will find more opinions on it.