Haebar, I'll relay my take on the meerschaum shopping experience, but others opinions may differ.
Starting with Meerschaum Market, as Ranger says their prices are erratic and of no indication of the quality of the pipe. If you handle one of their $150 vs $250 pipes, you may find no appreciable difference in quality, weight, size, or any parameter. In fact, I had actually returned a couple $150 pipes which mysteriously BECAME $250 pipes when I saw them relisted on the site! Further, their in-house brand SRV is priced comparably to some of the big name meerschaum makers but is basically only comparable in craftsmanship to garden variety AKBs which can generally be found for much cheaper on SmokingPipes.
I have ordered a total of 8 SRV pipes.. and sent back all 8. There wasn't anything glaringly wrong with most of them, but the overall attention to detail, craftsmanship, and stem shaping left a lot to be desired for the price. In a word, underwhelming.
AKB, the in house brand for SmokingPipes is generally a solid low- medium budget choice. You get what you pay for, but it's a good value. You often will not know the particular artisan who crafted the piece, their stems are not the greatest (very rare to get a stem that doesn't have at least a slight twist in it), and the buttons on the stems are usually too big to be comfortable. But, that said, they're a solid choice for the $100-$200 range and I've been happy with at least half of the AKBs I've bought. However, with a budget over $200, you're probably better off buying from a big name crafter.
In terms of big name meer crafters that I'm aware of, Altinay and Altinok are highly reputable and universally lauded for quality of the block, the craftsmanship, and the functionality. You will know exactly who made your pipe, you can speak to them personally, and you get numerous high quality photos from multiple angles. Since there's no need to rest meerschaums between smokes, you really only need 1 that you're happy with, which is all the more reason to treat yourself to a nice one if you have the budget for it. From my experience, one high quality meer of any given price is vastly more fulfilling to own than two meers at half the price! In hindsight, I sorely wish I had 2x less meers that were 2x more expensive.
I have an Altinay pipe due to arrive in 3 days, and I'll give you my feedback on what that's like.
By the way, I spoke with Said Altinay a couple days ago, and he mentioned that the price of raw meerschaum has gone up an astounding 420% in the last 1.5 years. He didn't mention why, but I imagine it has to do with both recent turmoil in Turkey as well as increasing scarcity of the mineral. Said is raising his prices something like 25% across the board for new incoming pipes, which is a ton, but is also justifiable. Buy as many meerschaum pipes as you can while you can! Before they're $1000 a pop.
