Ignore the pitches about a special sale going on for the next 3 days, or weekend, etc. - that is so over used, it's almost vomit inducing (seriously). Do not buy because you are being pressured by a dealer, don’t do it. There are a ton of hot tub mfgs and dealers around that they can lose your business to (and they know that), so, they'll do whatever they can to make a sale with you (which is good); including sometimes coming down to a reasonable and agreeable price. In fact, I’d say in many cases, the dealers anticipate the consumer’s desire to negotiate; so, thus, they have their tubs marked up slightly to begin with. Think about it, you do that, or any consumer makes an offer that is $200-$500 or so less than the sticker price, if the dealer “thinks about it” – and comes back and says, “sure” – you feel like you’ve won something and you’re almost certain to make the purchase on the spot. Just some points to keep in mind; not applicable 100% of the time perhaps, but I would say certainly most of the time.
Secondly, nearly all dealers include the cover, steps and some start up chemicals, so that is already factored into the price they are charging you - thus, in most cases, nothing "special" at all about them including that stuff (it just sounds nice!). And, some dealers factor in delivery as well; if not, I’d negotiate to have that thrown-in as well, or at least done for about half of what they normally quote over the phone.
Thirdly, the warranty. The least I have seen on a shell is 3 years by brands such as Dream Maker - to 5 yrs., 10 yrs. and lifetime. For $4600, that warranty just makes the "ok" mark in my book. I recently bought our rotunda style tub for $2700 and it came with a lifetime warranty on the shell; so, 5yrs. on the one (you are looking at) for almost $5K, nothing that special to me.
Finally, it's a buyer's market these days in my opinion - with the economy still making things tight (and hot tubs are still considered a luxury item), to the greater number of spa mfg that are popping up every year, to even the insane amount of new dealers who simply post on Craigslist and carry no inventory at all; I'd rarely consider paying any posted price on any tub (sale or not). If you can find out the list price from the mfg. that can be helpful, as I found in my early search, a couple times I was quoted above this price; which told me the dealer didn't want to mess with that tub for one reason or another unless it was really worth it for them (and I get that). So, since most dealers are not selling huge volumes of hot tubs, combined with the other points I mentioned above, your business is certainly wanted by that dealer; and in that sense, you can actually be in the driver’s seat to a degree in terms of working out the details of your sale.
Good luck in your search, I do recommend buying from a dealer you're comfortable with (vs. just online or from a box warehouse) and don't cave-in to any high pressure sale tactics if you’re not ready to buy. Most dealers do have overhead and other operating expenses, so they do need to make a reasonable profit; I don’t mean to sound like you can expect to go in and call all the shots; rather, you can most often negotiate a little to an agreeable price that makes the whole shopping experience a win win for you and the dealer.