It's tough to say. The RG1570 goes for about $500-$700 depending on condition. Unfortunately, when you modify a guitar, at best it won't affect resale value. Usually, it will devalue your guitar. Anyone looking to buy it is going to see a modified RG1570, not a JEM. Your pictures are way too small to show the condition of your guitar. If your luthier did a very good job at the modifications, you can expect to get the same amount of money for it as a regular RG1570, maybe $100 more because it's a lefty.