How do you buy ties?

I buy them impulsively. If I like it, I buy it. IMO when it comes to ties, that's what really matters. I personally think that a 120 - 140 € is the maximum amount I'd be willing to pay.

You can find some brands you know they make nice stuff that worth the money you pay for it (Marinella, Battisti, Drakes, etc.)

IMHO the most important thing is to make sure a tie knots well. You can get an expensive tie, but if the knot sucks it will most likely look like crap. But a cheap tie with a great knot can make it look more expensive than it actually is.

Knot + material + construction.

Knot: As Beatlegeuse commented, it MUST have a good knot when tied (note: this can also depend on what kind of knot you tend to tie/like). Just because it is expensive does not mean it will necessarily knot well.

Material: Stay away from blends. Look for all cashmere, all silk, all linen, all cotton, etc. Obviously, NEVER buy synthetic ties. Also, if a tie is made from 100% of the aforementioned materials but still feels flimsy or cheap to the touch, take a pass.

Construction: Depends on what you are looking for but generally ties come in 3, 5 and 7 fold construction. More folds does not necessarily make for a better tie, but it does mean more material was used in the construction, which generally makes it more expensive.

www.dieworkwear.com did a great breakdown on ties you might also want to look into.

Honestly, after buying a bunch of Tiebar.com ties, I'm done buying more expensive ties unless I see something at a store that really catches my eye.

I've paid up to about $120 for a tie, but didn't feel like it was a lot of value for the money.

I agree, the knot is the most important and then material and construction. However if you buy a good quality tie, the knot will be by default good.(that's why it's of good quality) the question is what kind of know you are looking for... if you like knot like four in hand than RLBL would be good but not good if you want a thick knot..
On the material side, most of ties are made by silk, but some feels really soft (good for a thick knot) some are not soft good for four in hand.. For myself i've just bought 2 sasks 100% cashmere tie on ebay for $80. IF you are tired of silk ties, invest in cashmere or wool ties...

Well, that's a very subjective matter, because at the end the fact of spending money on non-essential things depends on a number of factors, most of them not always rational.

I am not an expert, but I think it is more or less easy to spot the difference between a low quality fabric and a good one. In my experience good ties tend to be thicker, and the pattern is woven instead of printed. Also how it's made can give you an idea of the quality / price. For instance a 7 fold tie is an indicator of good craftsmanship as it's more difficult to make, and thus this can justify to pay a premium. Of course this it doesn't mean 7 fold is aways better than a 3 fold, because at the end many variables have to be taken into account, like quality of the fabric, actual expertise of the maker, quality control, etc.

If you go for known and reputed brands you'll pay a premium for this, but you'll be pretty sure that what you buy is good quality. But you can find many of these well known brands at discount prices so you don't have to actually spend full retail price to get them. If you want to get top notch ties at a very reasonable price I recommend to you to check the ties SF member davesmith is selling in the B&S sub forum. Specially the Battisti ones, they are simply incredible.

If it looks good, ties good, i buy it.

Ralph Lauren Blue Label

+1 for that answer.

I find the best maker of ties is Profuomo Good knot, hang well.

Material and construction are my two main priorities. I find that most ties will do a good know though the type of knot might become a factor. I generally don't spend more than $30 or so for a tie though. I might splurge once in awhile if I find something I really like.

For those of you who want a tie that knots well, do you tie it before you buy it? I guess you must but I am surprised that sales people are happy with that since tying it could make it look used, no?