Lots of people have started with an Ace 250, there are loads on ebay because people who stick with the hobby tend to move up to more complicated machines. Although some stick with their 250 for years and are happy. The great thing about an Ace 250 is how cheap you can get one to try the hobby out.
I started with a Deus Lite, that's the Deus without the remote, it was £550.00 but they can be picked up cheaper. I bought mine from a coin merchant after doing a few checks on his background. It had 4 years guarantee left on it, and with the Deus the guarantee transfers to the new owner, not all guarantees do that. The Deus without the remote is much simpler but still has great performance. If you like the hobby you can save up for the remote like I did and the machine becomes a more versatile machine with deeper programme changes for you to try.
I haven't seen much feedback on the Deus on wet sand but I have used it on dry sand and found some nice stuff, and of course it's brilliant on earth/land as plenty will testify. If you don't like the hobby you will sell the Deus Lite no problem without much loss.