Does anyone have any recommendations on where to get a custom touch mark that won't break the bank? I'm looking for something that can be used for both hot and cold stamping. I see a lot of cheap ones on Esty but they look like walls of the design go straight down instead of being angled like a normal metal stamp which makes me question their durability.

I get mine from Steel Stamps Inc. Best bet is to get ahold of sales and ask for a quote. 

There is a member here that makes good touch mark stamps. He has posted on the thread about them.

I can't control the wind, all I can do is adjust my sail’s.
Semper Paratus

 

I found the members log on it's  Stamp man  might try sending him a PM. Or google his business. He is who Glenn recommend to me. If I recall right my stamp cost under $100 U.S.

Columbia Marking tools company, (CMT)

I can't control the wind, all I can do is adjust my sail’s.
Semper Paratus

 

Depending on your design it is possible to make your own touch mark stamp.  I made my own.  My touch mark is the Old English rune for G which is an X with small diamond shapes to the left and right of the crossing or the X.  The problem is making interior shapes for letters, runes, or any design.  If you are making an A the problem is to make the triangle inside of the A above the cross bar.  Using a piece of spring as my stock I hot struck 2 square diamonds into the end with the side points almost touching.  I then lightly ground the end to get the scale off and drew an X with a fine felt tip.  I then removed the metal up to the lines of the X  and the edge of the recessed diamonds with a dremel tool and fine files.  I used the dremel for the courser work and the files for the fine, final work.  The trick is when you get close to the lines of the design not to take too much off.  You want the line of the design to have a V shape with a slight flat bottom.  

You will need a pretty tough steel if you are going to use it on both hot and cold metal.  I only use mine hot and it has held up fine.  

One of the factors affecting how well a touch mark stamp works is how large it is and how much metal you are displacing when you strike it.  You can observe this when using commercial letter stamps.  You have to hit an M harder to make the same depth impression than an I.

Whether this is feasible or not depends largely on how complex your design is.  

"By hammer and hand all arts do stand."

When I made jewelry, I made a sort of stylized R stamp that was quite small out of punch.  I first made a D shape punch and used that to create the negative space in the R of piece of stock that was to be the final tool while it was red hot.  Then I used files to remove everything around the D shape  that didn't look like an R and heat treated it.  It held up well but was mostly used in silver, gold and other nonferrous materials.  I did use it to make a blade on a miniature blade at least once.  Remember that your punch is a mirror image of the struck mark.  As George notes, the complexity of the chosen design may be a limiting factor in doing it yourself or a least make the job more difficult. 

YES!  Mirror image.  It wasn't an issue for me because my touch mark is symmetrical left to right.  A, H, I, M, O, I, U, V, W, X, and Y don't have this problem while all the others do.

GNM

I contacted Stampman to make mine and highly recommend his work. I PM'ed him from here and he contacted me in less than 30 minutes to discuss what I wanted, 30 minutes later I was contacted by someone in design and shortly after I had a proof in my email. Less than 2 hours it was on order.