You're asking about one subject in business study that could take up to a semester or more to really talk and understand about this. It's always a headache to marketing manager too on how to price its product.
Most of the high end product that has agent in Thailand don't care how much locals price their products. You could read more about this by clicking here,
Invaded by the Grays and it said this thing.
When we (XLO Electric's Roger Skoff) set up a foreign distributor he is granted exclusive distribution for a given territory, for his country. He is free to set up dealers however he likes, and to charge whatever he likes---which may be higher than the selling price in the States.
Some other example includes Sony MDR-E888.
US price: approx: approx US$70 (Bt2,800)
HK price: approx: approx HK$320 (Bt1,600)
Thai price: approx: approx Bt2,400
All prices are from Sony in respective countries. I believe Singapore's price is close to HK price. That's why US people will skip this E888 earbud for Grado SR60 and you find the same thing here for Grado SR60
US price: approx US$70 (Bt2,800)
Thai price: approx Bt4,000
I think they price products due to each individual market and the perception of the consumer for the product vs. others, ie how much they think consumer 'could' or 'would' pay for such product in a particular market. It's an 'art' more than a 'science' in trying to figure out this 'sweet spot' in a particular area and the marketing guy got paid a lot on this. Plus import tax on top for the stuff but I think tax these days is a rather minor issue. Anybody could help me on this.
Most of the audio critic in Thailand won't care about int'l price. They assume you can't get it at such price. You can test it by phoning in and asking this question to those people who hosted a radio station. The answer may be something

, oh! the extra is the need to prepare for aftersales service, blah blah blah but you know for sure it has less to do with it but more to do with how they want to sell you. To me, the Stereophile's article kinda confirmed this.
Also, local audio critics have no benefit comparing it on int'l price basis as they only get paid from local business, not int'l one, unless it benefited both the audio critic and local distributor, ie they sell it "less" than int'l price for whatever reason (you could find one of those reason in the Stereophile article above regarding gray marketing). So, if they said Pioneer is much better than Marantz, pricewise, then they gonna have difficulties when they go to Marantz for adverstising. Also, Marantz in Thailand is just an agent, unlike Pioneer which is a branch of the owner. As such, Marantz may have less bargaining power and may not want to see the market 'boom' too much. Otherwise, Marantz Japan may cancel its contract and came in to set up their own shop. With this one in mind, it's more likely you gonna have an 'untapped' potential all the time for brands that has an agent, instead of the owner, in a certain area. So, price is likely to be higher with the likely exception of gray marketing.
Now, how to compare.
I think as we couldn't get stuff easily outside Thailand, we have no choice but to use Thai price for comparison. Though I sound

all those audio critics but most of us has no chance to do that so in a way it's justified to do that. We could complain or show that the products charged extraordinary profit but I doubt whether that will have any significant effect. The original owner of the product 'do not' care about this one as long as the local agent could sell it.
One of the example that comes to my mind is B&W speaker. They even have the regional "branch" in Hong Kong and I'm sure they know about what's going on in Thailand. If you follow this webboard and are in the audiophile area for a while, you heard about the reputation of the agent of B&W in Thailand. However, nothing was done and the distributor of B&W in Thailand is still there till these days. So, I doubt our action means anthing!. If you don't

it, then don't patronize them. However, seem

people are OK with the comapny as they are probably one of the longest agent for a certain product I know of in Thailand. I heard recently that Musical Fidelity (MF) also set up their own shop in Hong Kong, likely for regional headquarter couple of months ago. It will be interesting to see the activities of MF brand in this part of the world
Of course, if you could get it from somewhere, then it's another story.