Is this a good trade?

The rule of thumb I use when it comes to firearms trades is this: if you don't know for sure that it's a good trade, it probably isn't.

In this case, though, it might be- emphasis on MIGHT. If the person will allow you to shoot their XD, do it. You need to make sure it's feeding properly with each magazine. Buy a box of ammo and load 10 rounds into each magazine, and shoot each one. If one of the magazines isn't feeding well, make note.

Basically, you should be able to make it through a box of ammo with no real issues. If there are any misfeeds, I'd be hesitant to buy the gun. Check the magazine for damage, just to rule that out.

Here's the kicker. Your rifle, as is, is probably worth a bit more than the XD. An XD sells new for around $550-$600. Your SPS sells for somewhere around $600 or slightly more. The scope you have on yours is nothing special (BSA just isn't a top-tier optics manufacturer), but it would be worth at least $50, I'd say. The bipod, if it isn't a cheap clamp-on, would be worth $25 or so. Considering that the XD has more use than your rifle, it will have taken a very slightly bigger hit on value.

Tell him you'll trade it, but that you would like an extra $100 or so. The extra mags he has aren't necessarily worth a dime- if they don't feed properly, they're worthless. The holster, likewise, may not be worth anything TO YOU. If it's a cheap Uncle Mike's holster that's mediocre at best, it will be uncomfortable to carry. If it's an expensive holster, but it doesn't fit with your body style or preferred carry style, it's still worthless to you, except as a Craigslist piece.

I'd say that the trade isn't horrible, but at the same time I'd be VERY careful. Like I said, check the pistol for function. TWO boxes of ammo would be a good test, honestly.