The lowest price of add-ons in the Marketplace is $15. It has been created this way to prevent a "race to the bottom", but also to encourage that developers are compensated. If it saves 10-30 minutes of your time (depending on your pay rate), you can figure that its less expensive to buy a $15 addon than to do it yourself. I find code highlighting and completion to be very useful, so you might even consider it to be a "creature comfort" issue and not even so much about whether it can be done otherwise. If it makes your life better, budget for it when you bill your clients.

Thanks and I hope you have a great day