Redhat,
Before I start, let me say I own a Hornady LnL, a Lee Classic Turret and have a Lee Classic Cast single stage on order. I've also owned, in the past: A Dillon 550, an RCBS Rock Chucker, an RCBS Partner press and a LymanT-mag turret press. I have friends who own Lee Loadmasters, Pro 1000's, Lee's older style turret and Dillon's 650 progressive. I've loaded on their presses as well. So I have a good bit of exposure to a number of presses. I started out with an RCBS Partner press and learned to reload on it. Note what I still own, (The Lee single stage is my second one, a son "borrowed" the first.) and what I don't.
That said, each person has a different style of reloading and different objectives, so let that guide you in what you're buying.
"With recent increases in ammo prices and my XD45's never ending appetite, I've decided to take the plunge and start reloading!"
Good choice in caliber and an easy round to reload.
"I am at a decision point and would like opinions."
My vote is for the Lee Classic cast turret press with a safety prime, Lee deluxe 4-die set and a Pro Auto Disk Powder measure. It'll give you 200 or better rounds per hour, is very affordable, allowed you to have excellent control of the ammo you're loading, loads accurate rounds (I'm loading a lot of very accurate surplus ammo on mine.), is a very high quality machine for not much money and is generally a fun press to reload with.
"Two men I respect adviised me to start with a Dillon 550 or Square Deal, however, I like the price and capability of the new Lee Classic turret."
Those are good presses, but neither one is a "best buy" these days. The 550 is manual advance and for that much more money than a Lee Classic turret, I'd want automatic advance. The Square Deal B uses non standard dies, so you'd be stuck using only Dillon dies, plus it doesn't load rifle cartridges. You can buy a much faster press than the 550 in the Hornady LnL for about the same money as the 550 (no casefeeder) and you can buy a much more flexible press than the Square Deal B in the Lee Classic Cast press for less money than the SBD.
"I only shoot 45ACP right now and don't anticipate changing."
Then the Square Deal B might be for you, but would you want to tie yourself down to only one press and have to buy another if you change your mind later? I wouldn't. I'd want to be able to have the option to upgrade or not, which the Lee Classic Turret press will give you.
"For a beginner it seems as if the Lee's price is right."
If the Lee had been available at the time I decided to upgrade from the single stage press, I'd have saved a lot of money and would not own a Hornady LnL right now. Unless you have little time and lots of money, the Lee is plenty fast enough for the average reloader. I've shot IPSC and High Power and never needed any more production than the Lee provides. Faster is a good thing, if tmie is extremely limited, but sometimes simplicity, cost and control of what you're doing is more of an issue. The Lee classic Cast turret, setup with a Safety Prime, a set of Lee Deluxe dies and a Pro Auto Disk measure provides a really great platform to not only learn how to reload under control, but to produce a reasonable amount of rounds per hour.
"The Dillon is much more expensive and I am cautious about dumping that much money at the beginning stages."
You, Sir, are a wise man. I applaud your common sense and frugality. Even if you invest in a progressive at a later date, you'll still find good uses for the Lee Classic turret. I found enough use for one, I added it to my stable of presses. One reason was because it is very inexpensive to add a second caliber to it.
A statement was made in the posts above about another brand of turret being the "best." I think this article addresses this:
http://www.realguns.com/archives/122.htm
Check out the link. I think you'll find the article interesting reading. Shows the setup and everything involved as well. It's an easy press to setup. There's some tuning tips I posted in a couple posts. If you do a search of my nickname, you can find the tips for extremely smooth press setup and operation.
Regards,
Dave