You don't provide quite enough data to answer the question. Presuming you own a home as a residence and not an investment property, and you have found a home in another location that has a home owner who wants to "swap" their home for yours, so you don't get screwed in the process, you should at the very least enlist the services of a licensed appraiser to appraise both properties to ensure that what is being traded is of equal value. Or, to determine which side of the transaction owes the other money.
If on the other hand you don't have the other home identified, the likelihood of finding another home buyer willing to swap, in the total scheme of things, is extremely, extremely small.
Realtors in this kind of a situation could add value, but again, there isn't enough info in the question to determine if that makes sense. They will certainly add cost to the transaction since no one works for free, but the fee to do this can certainly be negotiated, if in fact you already have some sort of discussion going on with another home owner. There's no reason to presume you should have to pay the typical commission involved in listing your home for sale because your sort of bringing the deal to the agent.
Hope this was helpful,