GVPCB is a definite staple of mine, for sure! I highly recommend giving it a try - plus the price is great!
Another I love - though I cannot compare it to One Condition, is Shea Moisture Conditioner. (I think it's called "shea moisture replenish conditioner") I use it as a LI, though. I doesn't have good slip for me, but as a LI it's lovely!
Again I can't say how it compares to One Condition (I've only used that once), but I can say it's $10 for 12oz, is often on sale, is available at Walgreens or Target (and online at either store), and is very moisturizing!
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