Its only worth the Trade if you are getting a guitar you can use and 'bond' with. Trading guitars, as long as its got all the case candy and case of course is unlikely to see you out of pocket because you would lose more by trading the LP in store and with the amount of LP's listed for sale, chances are you will not get a 'great' price.
I see a lot mentioning 'value' but having a guitar in your collection that you can't bond with and unlikely to play - especially as you have 2 others you are much more likely to use - has very little value to yourself. Its just 'dead money' so to speak. Of course it has some worth to someone else and they may be willing to pay (or in this case trade) but to you it has little value. If you like the Custom 22 and enjoy playing it, enjoy the tones you get, then that guitar has more value to you than your Les Paul.
As they say, everything has a price but because I love all my guitars, they have a LOT more value to me than their worth on the market. For example, if a used 2018 Custom 24 in mint condition is worth £2.5k and a new non 10-top one (like mine) costs £3.3k, I wouldn't sell mine for either of those prices - someone would have to offer a lot more to meet the 'value' that instrument has to me. If I didn't bond, the most its worth is £2.5k but a trade in a shop wouldn't give me that much against a guitar I did bond with and selling privately, there is a point that you will let it go for because people will try and offer what they think its worth (or under to try and get a bargain) but I doubt any would pay more than £2.5k. The reason for this paragraph was to illustrate the difference between Value and worth - at least how I see it.
Its clear that the value of your LP is at most, the worth - as in its used price - because it has no 'value' beyond worth to you. Its dead money because its tied up in in the guitar essentially and whether the Custom 22 is 'higher or lower' in worth, it could have a LOT more value to you if you actually bond with the instrument, The only time the deal should be considered in terms of worth is if you are trading one instrument you have no value to you personally for another. If you end up not bonding for example, then the 'worth' becomes more important.