I agree with Ellisandra.
If you can afford to save, then save in whichever investment suits your risk appetite - in the UK, people seem to like property but I find stocks and shares ISAs work very well for us for amounts like £15K. Remember to use all your tax shelters like ISAs, JISAs, and pensions (especially if you are higher rate tax payer).
When your ds is 18, you may very well have higher paying jobs that you can use to fund his university fees and expenses out of income. It is what we plan to do for our dcs.
By then, our mortgage will just about have been paid off (as we have been massively overpaying to meet the deadline) and this frees up our cash to use for their accommodation and expenses. We will fund tuition fees out of income.
In the meantime, we might get an inheritance but we are not counting on that.
I have costed their uni education at about £50K for a bachelor's degree but thy youngest is at most 5 years away. Your dc is much younger so makes sense to shoot for a higher amount, with inflation etc.
If you don't make the target, there is always the back up of student loans. It is a nice thing you are doing for your ds.