Most of the insulin do come in a reusable pen system...
Most companies to have a range of pens, that are either plasitc or metal, lilley and novadisk have both types..
I think it hit and miss to which type last the longest, as when I used them I found that some would last for years, and only need replacing because the numbers had worn off, and others have failed..
If changing or have a reusable pen, it is wise to ask the doctor to prescribe (or just request on repeat as mine are on repeat) a spare pen (each type if using two different makes of insulin) so that you always have a spare pen..