I bought the Givens Bouy back in 1976, I just looked at the current prices and had a bit of sticker shock. They were expensive back then but WOW the prices today. Still the big convincer for me was the insulated floor. I had worked on The TAPS project and had spent a couple of winters in Alaska. To me a huge problem is hypothermia so it was the insulated floor which sold me. At that time tht was a feature that Givens had and many/most did not. I also bought the 6 person model as I don't know how 4 people are supposed to survive in the small space of the four (any of the models designed for 4) especially if one is hurt and needs to be horizontal. Also I want to be able to save as much food water etc as possible and stuff takes space.
When it comes to servicing a
liferaft check with your local major airport. All the rafts on international flights have to be serviced regularly and by dealing directly with the guys who do that servicing you can remove the middle man...that's the guy at the boat shop (that's where he will take your raft).
While in Hawaii I made friends with a guy who worked for such a facility. He shared with me some tricks to servicing
life rafts and walked me thru doing it myself. I have repacked mine three times at quite a savings (needs it again). Since the raft is mine and I am the one who will suffer or benefit from customizing my raft I changed out alot of the included "provisions" and updated to a water maker (rather than a fixed number of cans of water) and included a deck of cards (plasticized) with cribbage board. All in all the hardest part about repacking one's own raft is getting it back into the canister (the same configuration of folds etc. as it came out).
There are a couple of tricks to servicing a raft: Don't pull the cord to inflate, this freezes the material near the connection of the cylinder to fabric and one risks cracking (it only has to survive one fast inflation). And so inflate using the hand/foot
pump to your inflatable boat. And take photos for each and every step (back when I first did mine I actually used a whole roll of film). The usual time left inflated with no loss of shape etc. is something like 24 hours. When ready to deflate, again use the hand
pump but instead of inflation use it to deflate (extract the air) from the raft And as you do recreate the same folds as the raft was packed originally. Other than that it's a piece of cake, the cylinder has a gram weight and so simply weigh the whole and if it's off by much take it to a testing facility where they will test and refill the cylinder to the marked weight. Some may want to do this part anyway as a check that the valve on the cylinder works, I did mine the first time.
This is more info than you wanted but I included it because I would have no problem going with a "second hand" raft, provided I could service and inspect it prior to purchace.
Hope this helps.
Wiley