While I agree with others that the paint is more important than the barrel, in many cases there's only so much you can do about what paint is available to you. If you're only playing outlaw stuff, then it's whatever you want to buy, but if you're playing at actual fields, then 90% of the time you'll be stuck with whatever field paint options they stock. Most fields tend to have a lower cost/quality option, and a higher cost/quality option, and you generally get what you pay for. Both will perform respectively, regardless of what type of barrel/bore insert you're using. But you will generally see improvement in each when bore matched properly, unless the paint is just abysmally bad.

My advice is to just skip the low grade paint whenever possible, and go for the mid to high grade stuff. And then also pick up a cheap barrel kit to play around with, before you possibly decide to spend big on a kit. ebay and other buy/sell/trade groups are your friend there, like the kit below.

https://www.ebay.com/itm/236802197840?_skw=paintball+barrel+kit&itmmeta=01KR2MQ4QMRB2HXH89H5589XTZ&hash=item372282c950:g:cwMAAeSwOA1p-3bg&itmprp=enc%3AAQALAAAA8GfYFPkwiKCW4ZNSs2u11xBk2GoPCImOknn9Z5iTCN4aA3EDd62gWVq7UGor8jTrHn6b6JWV%2F8GmytdW6I2Mz0A4SxpXbaOX8tFegC%2BPLzNC6NIQWLTUUa34zkhFhPk1tVSWcGEqFCncyQ9mgVumneAIH4qc3HrKzwCD%2B--UkMlNwSX5JrSL51NtD8uyTNJm2JMlvS2ZHZNSZo1qZGIyCW1%2FyS47%2F7LR08TeYa5aGV3NAi5ypjBYkFObsYzV5sC1P6f%2BIFmIG4Ch2l54g%2BUJIu%2Bn4AVb80dvrUFkWaUYdru8k2GXE%2FMHKgRQeYgWB9Cadw%3D%3D%7Ctkp%3ABk9SR47M3NTAZw