I actually found my Webasto two days ago at an ebay seller for $683. That was about the best price. Several years ago I paid about 800 or so for it. However, it's the rest of the stuff that adds up quickly. The fuel tank with hoses and filter is $115, but then shipping added another $29. The exhaust thru hull is $147, 1' of insulating jacket that wraps around the exhaust pipe is $21 and I bought 3' just to make sure I had enough. The bracket, which one could probably make cheaper, but just makes installation a lot easier, was $51. Total cost $260 + $21 shipping. If you live in Washington near Sure and Scan Marine, you could save $50 on shipping. When I installed the Webasto in Midnight Flyer, I spent a lot of time tracking down everything I would need. I don't know if you can find the extra stuff for less at other dealers, but I didn't then, so I just used the same shops to buy that stuff again this time. You can find the Webasto Heater easily and just chose your cheapest seller. However, this is not a marine unit. You can just about double your expense by buying a marine kit thru a marine outfitter, and then you would get everything you need.
Regarding the Wallis, my wife and I discussed that stove/heater and I have discussed the Wallis with several other boaters. From what I understand the Wallis runs all the time if you use it. You can turn it on low or high or anywhere in between. However, it doesn't kick on and off like the Webasto or a regular furnace, to maintain temperature. So you could end up overheating, or not having enough heat. Most C-Brats I know that have a wallis say they turn it off going to bed, then turn it back on to take the chill out of the boat first thing in the morning. The only thing I don't like about the Webasto, is it is kind of loud. Like a mini jet engine firing up. But it puts out the heat when you boat in some really cold temps. I used it boaterhoming home a few years ago, where the outside temp got down to 18 degrees at night. I still woke up with 60 degrees in the boat. I only had one time where the Webasto stopped working and gave me an error code. It was during that same trip, and I don't know if the fuel had some moisture in it or not. But after shaking the tank a little, moving the pickup tube, and attempting to restart it several times, it finally lit off. The next day I dumped some "heat" additive in it, and didn't have any other problems. The other reason we decided not to go with the Wallis is my wife wants her countertop space. And a brand new Wallis is $2800. So, not putting Wallis down. It's just that the Webasto serves our purpose much better.
Alsp there are some really cheap Chinese knockoff units out there, and I know at least one C- Brat that bought one and installed it and I think it worked well for them. I asked our mechanic at the school bus garage about the units. He use to service semis, and stated the Webasto's were solid units that held up very well, and that I should stick with that rather than going to a knock off.
Colby