When you say

you have been offered

did this come in a telephone call or some other cold calling method. If so then please be very wary of it i tried a google search for the company and it came up with zero hits. I would treat this with extreme caution although they say they are not timeshare it could be a holiday club and those should be treated as timeshares under a different guise.

I only found one reference regarding Medsun and it was for Medsun Holidays a that was company dissolved in 2003.

I have it on good authority that this will be a fly buy deal. They will be offering you a holiday package which means that you are under obligation to sit through a presentation, which can take hours!! Plus they are quite hard sell. But if you dont mind that why not take the cheap holiday, you may have to buy your own flights and it may work out cheaper and easier to book a normal package with a reputable company!