Every Sissy will need certain items for your training. Some items that you will have to have include:
A wig
Makeup foundation, contouring, blush, eyeshadow, eyeliner, mascara, lipstickgloss
Bra and panties; a padded pushup bra is a good choice. You should consider at least 7 pairs of panties, you will want to have a clean pair everyday.
Lingerie including g-strings, garter belt, etc.
Corset
Feminine outerwear such as dresses, skirts
Heels
Stockings, hosiery, thigh high socks
A Lady Bic, and wax for removing hair
Moisturizing lotion
Toys buttplugs dildos etc
Chastity cage
You may want to look into herbal supplements for estrogen
Yes, being a sissy can get pretty expensive.... you don't have to get everything at one time but you can add to your inventory as your budget allows.