How To Value Stamps From Sheet Edges

I'm very much an amateur and am just starting to see stamps I'm interested in that will have one or two imperf sides if they're from the edge of the sheet. If you're considering a purchase, how do you value them? I'm having trouble finding that information.

I see that The Philatelic Foundation won't grade these stamps. The document I read from the Foundation doesn't say why, so I'm not sure what the rationale is there. Does it make the stamp so undesirable that they won't bother or is there another reason?

On the other hand, I could have sworn I read from another source that straight edges caused by the sheet position technically do not change the catalog value. Now I can't find the source though.

Clearly it has an impact on value though because reperfs have been done in attempts to make these stamps more desirable. What do you think? Say you have two stamps, both MNH and of comparable grades except one has a straight edge and the other doesn't. How much would you want the straight edged stamp to be discounted? Or would you go so far as to suggest staying away from them entirely except as a filler to be replaced later?

More info here https://stampsmarter.org/learning/I...reLines.html

Over the years, many collectors avoid them and prefer fully perforated stamps. With lower demand, the market values were (are) lower.

A few collectors used to collect 'straight edge' stamps and try to get all the positions in a sheet, but these collectors are not common today.
Don

Most collectors, given the choice between a stamp with 1 or 2 straight edges vs a fully perforated stamp would choose fully perforated. In some situations, some may consider a straight edge stamp, for instance on a very high value stamp so they can fill an album space. Or, maybe looking for position stamps. Straight edge stamps are typically valued less than full perforated, but I'm not aware of any general percentage as it could vary by issue.

This recent discussion regarding a high value US classic stamp with a straddle margin gives an idea of the difficulty in selling perforated stamps that have one or more sides straight edged:

http://goscf.com/t/82583&SearchTerms=100

It's actually very difficult now to find straight edge examples of many high face value/cat value classics; people have been reperforating them for many decades.

I've seen a couple recently on E-bay for stamps that I'm interested in. They look to be significantly discounted. I'm still a little torn on it. I don't want to feel like I'm overpaying for something, but I also know I shouldn't get too, too hung up on resale value as realistically I'm not going to make money on my collection. That kind of goes for anything people collect. Some dream of making big profits on their collections someday, but most people never actually will. That's not why I do it.

Thank you for the responses. Very informative. I probably try to pin down a specific percentage discount as I'm a software developer and we don't like things to be vague. Hah.

I try to keep straight edges out of my main collection but I don't avoid them completely. When given the choice, I prefer a stamp that is well centered with nice margins even if one side has a straight edge, instead of the same stamp that is off center with narrow margins or perfs close to the design. I have some off-center stamps in my collection that stick out like a sore thumb and I want to replace, and others with a straight edge that I am quite happy with. It is all about the aesthetics and personal taste.

When comparing two stamps side by side, the one with the straight edge is usually less desirable but not always. It is just one factor that affects the price, but not by a specific amount. It is a sliding scale. I would also prefer a well-balanced nice-looking stamp with a straight edge over one with a bad reperfing. The straight edge is a natural phenomenon, the reperfed stamp has been tampered with.

But that's just me. I am one of those rare collectors who also collects matched sets of all the positions of straight edges. 51studebaker, what is the name of that catalog or price list that you pictured? $15 for a 293. Nice!