Costs are usually just the shipping fees there and back for the monitor within 30 days. It normally takes as long as making the monitors the first round. They basically take the your monitors and recreate another one using the materials from your mal-fitted CIEM. Of course, you'd also have to provide new impressions, which could be the root of the problem. And even with perfect impressions/perfect craftsmanship from the company, there is still a risk that it won't fit properly because your ear is a dynamic cavity while the CIEM is static. Silicone CIEMs are more forgiving as they are more pliable in the ear.
I know this might be out of your budget. But FitEar CIEMs have gotten down to some formula where many do not require a refit. I have no idea how they do it, but I know they're strict with the way they want their impressions. Although they are acrylic, some say that they have seal capabilities on par with Silicon CIEMs. But that's a thought for the future. I might travel to Japan to purchase one in the near (1-2 years) future.
FitEars are definitely out of my budget haha. If I ever have the pleasure of visiting Japan, I might get myself a pair. I wish more of the companies would provide silicone CIEMs, but I am guessing that is more expensive to do. I still can't decide between the Heir Audio 8.A, JH16s and Merlins :(
I'm always surprised that the jh13 is left out of these compares. People really under rate it's bass response and the rest is detailed with less etch than most. It does not have that extra mid bass that overly warms the mids but once run it in well enough, the mid bass lines up well in connecting the prodigious low bass to the well balanced mids and top.
From what I have read, the JH13 don't have as much bass as the JH16, since I really like my bass, it seemed appropriate to choose the JH16.
Right now I am confused as to a DAC/AMP combo as well. A HP-P1 or a CLAS R paired with a E12 or something similar, can't have it being too expensive.