I have a client right now who wants to do a trade with me.

They want to exchange their services against my fees - the problem is, their services retail something like $1000 per hour VS my rate which is currently a median of $45 an hour for them. I can usually bill up to $100 an hour or more depending on the work or the client. I'm very specialized and have a lot of experience, but I usually keep it to a lower rate for smaller businesses like theirs. I often offer deeply discounted rates when I meet people and realize I'm dealing with small business rather than a corporate entity, especially if they are nice and the job is interesting.

How do you think I can set that up to make it a fair exchange for both parties, so that it's not so disproportionate? In other words, how is working 20+ hours for their service any different for me than working 20 hours somewhere else and bringing that money to them to pay for the treatment? I'm probably missing something completely obvious, but I can't help but feeling it's not a good deal for me.

On the one hand, I know their equipment is expensive, but they would be billing me at a full retail rate; it certainly doesn't cost them $1000 for one hour (so they are making money on the session). On my end, I actually would have to put in 20+ hours of labor to make up for it, during which time I'm not billing other clients my full rate. They are getting a good rate, I'm paying full retail.

Any suggestions, ideas on how I can set this up so that it's fair to all involved?