Hi,
I guess that using the price limitation on manual shipping methods would be the best solution.
No need to change the weight, directly the right need, etc.
Just use the "minimum price" and "maximum price".
And you would have to create two manual shipping configurations but not having twice the plugin. This plugin allow you to create several configurations for different restrictions.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.