Getting the best performance depends on three things: beam alignment, quality optics, and focal point. Beam Alignment isn't something to be feared, it's something to be mastered if you want to produce the best possible work. Watch as many videos as possible (we have many on this site), until you completely understand this concept and have mastered the process. Super flat mirrors and a high-quality lens are going to produce the best results. They are not going to be the least expensive, but if properly cleaned on a regular basis, they should last several years. To obtain a consistent and accurate focal point, it is important to have a level bed and to perform a ramp test. You can have the best optics in the world, but it only matters if the optics are clean, the beam hits as it was designed, and you have the correct focal point.
If you want to upgrade your optics, or if they become damaged, a quality replacement is offered by American Photonics. It is a family run business in the USA. Use Discount Code LASERS123 at checkout to SAVE 5% on your entire purchase.