Laser.
huh? Yep.. laser... based on the information you provided and the question you asked.
If it is primarily a home defense gun and you DO have a fanny pack that you already carry the gun in sometimes (and I'll roll the dice on assuming you actually have practiced with it and know how to deploy the gun efficiently), then the laser grip is going to expand the conditions under which you can use the gun for protection without much training or practice.... whereas the holster will not. Buying the holster then requires that you spend a pile of time (and some ammo) learning how to deploy the gun from the holster efficiently.
Now, the fact is that the Holster is a <$75 purchase and a laser grip is 3 to 4 times that is worth talking about. If you can magically pull other out of a box and get/do nothing else, the Laser instantly makes you "better", but you could probably pay for the holster, the range time and the ammo to get confident with it for what the Laser Grip costs. SO, if you WANT to carry in a holster, bite the kydex and spend $300 to own a good holster and pay for the time/ammo to (start to) get competent with it.
OTOH, as noted above.. if you HAVEN'T trained with your pistol and fanny pack, I agree that you should put the $$ towards a good defensive pistol course.
-RJP