integration dokan / wordpress

We built a website with Dokan on wordpress and have a client with a special request (see below). the standard configuration of Dokan doesn't allow this so we would need someone with Dokan expertise to fulfil the below requirement: I've copied and pasted the types of postage options he needs (on top of spend over $140 for free shipping & he also needs a minimum $30 spend on his shop). In a nutshell he has products at 400g - 500g for $7.95 postage / and 2kg for $12.25 postage. NATURAL BIRCHER 450g CLASSIC 450g GLUTEN FREE 350g CLASSIC STYLE 450g COCONUT & CRANBERRY GRANOLA 400g CACAO & COCONUT GRANOLA 400g PALEO GRANOLA 450g 1 UNIT = $8.25 2-6 UNITS = $13.50 7-8 UNITS = $17.50 9-10 UNITS = $30.00 PALEO MIX 500g 1 UNIT = $8.25 2-5 UNITS = $13.50 6-8 UNITS = $17.50 9-10 UNITS = $30.00 NATURAL BIRCHER 900g CLASSIC 900g GLUTEN FREE 700g CLASSIC STYLE 900g 1-3 UNITS = $13.50 4-5 UNITS = $17.50 6-8 UNITS = $30.00 ALL 2KG PACKS (ALL 8 VARIETIES) 1 UNIT = $13.50 2 UNITS = $17.50 3-4 UNITS = $30.00 5 UNITS = $43.50 6 UNITS = $47.50 7-8 UNITS = $60.00 I'd prefer it not to be in units rather weight as this was taken from the Aus post requirements.