I just enioy the color more, lolWhy 450nm? Is it because you believe it will be more powerful? You might want to go with something in green. You can get a 532nm #303 laser on eBay for ~$5.00. It will likely be more visible than anything you can get in 450nm for $40.
yes,1w450nm is enough for start with laser,but i think 40usd is not enough for custom build,agree with youHi As Trin said a 1W would be fine , I make them in a 501B host and they take 2X18350 batteries. And it all depends how much you want the spend on a custom build too. Yes if you go with a cheaper unit online there are plenty if you find the right vendor