Well, I recently posted a thread inquiring about good full suspension bikes, but decided that I will just go ahead and save a bit more money and buy a Forge Sawback 5xx. It seems like the best bang for the buck in my price range with fully equipped Shimano Deore componenes, full Avid BB-5 disc brakes, and a rockshox dart fork, etc.

But, I really don't like the way hardtail bikes ride and am used to a little suspension on my rear, so I thought I'd just get a nice suspension post or a decent suspension seat. I don't know which one is cheaper, but I am leaning towards a post because the Sawback comes with a WTB Pure V Sport seat, while the post is a no name adjustable Alloy 30.8X350mm with with a quick release mechanism.

As far as seat posts go, I have heard that Thudbuster makes a good suspension post and that brooks makes a good suspension saddle, but they are both really expensive and I am not an extreme mountain biker or road biker. I am basically looking for something that can sort of emulate a full suspension bike feel on a hardtail, but without breaking the bank.

Any suggestions would be greatly appreciated.

Can vouch for the Thudbuster. I use it on the Tandem and "Who needs full suspension?"

It is pricey but it works. Even on the biggest of hits offroad.

But if I had a choice of good front suspension or a thudbuster -I would put the money into the forks. You can always lift your butt off the saddle on a hardtail (Unless it is a tandem and you don't get any warning)

There are low cost telescopic seat posts with springs in them, they tend to be 1"/25.4mm.. OD,
but there are Shims to fit the ID of your seat tube..
heres one with several sizes, up to 27.2..
https://www.sjscycles.co.uk/tranz-x-s...post-prod1734/
In the US QBP will have several, down to $25 in cost..

and Shim tubes too.

The best suspension is a sprung leather saddle.

There is no stiction or moving parts to wear out. There's the Brooks B-67 and the B-17 top with springs, the Flyer.

Pricey to be sure but the comfort can't be beat.