This isn't a cheaper option as far as the product itself, but if you find mixing FSG and HESMU isn't enough hold, you can try mixing BRHG with it instead. It's similar to SMU, but even stronger hold. I got mine for $12 - a lot pricier, yes, but I'd you mix that with something else, it'll go a long way. I use a dime size mixed with other gels or FSG, and I have long, dense, absorbent hair!
Try the HESMU first, of course, but you might give that one a try, if it doesn't give you the results you want.
2c/3a/3b, Fine/med, Dense, high porous, & normal elas.
Lo-poo - Renpure Keratin, SMR, Giovanni SaS
clarifying - mix Johnson's H2T with low poo
Co-wash - Suave Nats. clar. or coco.
RO - GVPCB, Ion Eff. Care, TN.
LI - SMR, Cure Care, or RO
Seal - MO or Jojoba
DT - + honey, ACV, & EVOO to SM masque & GVPCB
PT - Gelatin!, CNPF
Styling - FSG, AIF, BRHG, LALS/PS, GF curl spray gel, SM Souffle/Smoothie, LOOB
Oils - MO!, EVOO, jojoba, GSO, SM Elixer, EVCO, VO5 Hairdressing