I have treated myself to the Charlotte Tilbury airbrush flawless foundation and I really like it but I find it very stiff to apply - unlike other foundations it doesn't glide on as I would like. I know I probably need a primer underneath but I just can not afford £40 for CT primer. That would have been £95 on make up in one hit and with school uniforms etc this month it is impossible. Can anyone recommend a cheaper alternative primer that I could try that may work well with CT foundation.