Using a face mask once a week is good for your skin. I like Trilogy Purifying Masque, $33.90 for 35ml. Evolu Purifying Mask $35 for 75ml, is also good. Although both these masks are for all skin types, they are clay-based masks, which are good for oily skin, as are mud masks. Another clay mask is Dr Hauschka Cleansing Clay Mask, $62 for 90g, which is in the form of a powder which you mix up with water. I didn't realise that it was a powder when testing it out at Farmers once, and spilt quite a large amount of it on the ground. Anyway, moving on from that...
People with drier skin will benefit from a moisturising mask in a gel or cream form, like Living Nature Ultra Nourishing Mask, $59 for 50ml. As for those with sensitive skin, try Weleda Almond Facial Masque, m$22.50 for 30ml.
Some other options
$10 and under: Clear as Mud Face Mud $4 per 18g sachet, Skinfood Mud Masque 100ml $9.99
$25 and under: Clear as Mud, $24.99 for a box of seven 18g sachets
$30 and under: Weleda Iris Intensive Treatment Masque 30ml $25.50, Alba Botanica Hawaiian Papaya Enzyme Facial Mask 85g
$45 and under: Living Nature Deep Cleansing Mask - 10 5ml sachets for $42, Living Nature Hydrating Gel Mask 50ml $42, Antipodes Manuka Honey Treatment Mask 75ml
$80 and under: Ren Multi Mineral Detox Facial Mask 50ml $69, Ren F10 Enzymatic Skin Smoothing Facial Mask 50ml $74, Ren Jiaogulan Cell Energising Facial Mask 50ml $76
$90 and under: Dr Hauschka Firming Mask 30ml $89
$120 and under: Aveda Deep Cleansing Herbal Clay Masque 125ml $102, Aveda Intensive Hydrating Masque 150ml $117