question about resizing a blazer.

so, for christmas my parents bought me among other great clothing things two Polo Ralph Lauren Navy Blazers at $1100 a pop and a Ralph Lauren Tweed Jacket $1200 at the time. I'm not listing the prices to brag, but to express how much was invested in them, they weren't thrifted or found or whatever. Anyway, I got them tailored to me, didnt need much. My question is, that I'm heavier, and hope to lose weight in the near future, does my parent's investment of these clothes go down with my waistline or can I have them tailored to fit me when im 20 lbs lighter? I also have a number of Brooks brothers Suits that may also need some resizing how involved is that? Cost is not so much an issue as long as i save more than the ~3500 my parents spent on these clothes. Thansk MFA!!!