I get along nicely with carbide tipped tools. The tips are fairly cheap and last a long while. On the square tip you have four cutting sides, on the round tip you can rotate it when you feel that it's blunt, and the diamond tip (which I use little), has two ends to it.
It's a lot cheaper if you make your own tool shafts from either round or square section bright mild steel, and turn your own handles. I decided to give them a try when I watched this Craft Supplies YouTube video about turning pens with carbide tips:
Turning a Pen with a Carbide Turning Tool (How-to Beginners Guide) - Bing video
A set of six tips (two each round, square and diamond) plus six screws can be bought from UK suppliers on eBay for under £20.00 currently. EG: £16.68 + £1.68 P&P:
New Carbide Tips Inserts Blades For Chisel Cutter Wood Turning Lathe Holder-Tool | eBay
There are lots of videos on using them. This is part one of a three part series:
Part 1 of 3 - Woodturning: Can I do it with carbide - Bing video
I know that not everyone wants to be bothered with turning their own tool handles, but it seems to me that there's a certain irony as woodturners, in buying them rather than turning them. I just use whatever scraps of wood are to hand - ash, beech or whatever.
The handles in the pics below were from bits of spalted beech. I drill the end of the blank into which the tool shaft is to be fitted using a drill in a Jacobs chuck in the tailstock with the spindle supported by a lathe steady. Then I remove the 'steady' and turn the handle between centres, then use the lathe steady again to part off the other end of the handle.
Incidentally, the 'square' tips' are slightly rounded so the corners don't dig in. The round tip when held at an angle and used as a sheer scraper gives a nice finish off the tool, calling for minimal sanding. Likewise, I use the square tool for pen turning, with minimal sanding.
The last pic is a walnut pen with a Celtic knot. (The white inserts to form the knot were from an out-of- date credit card).
Hope these personal observations on my experiences with carbide tips are useful.