Offshore wind power is a crucial component of the global energy transition, with significant potential for large-scale power generation. However, traditional power frequency high-voltage AC (HVAC) transmission faces limitations for long-distance and large-scale offshore wind power transmission, particularly due to the charging current of submarine cables. To address this, flexible high-voltage DC transmission (MMC-HVDC) has emerged as a preferred solution, although its cost and complexity remain challenges. Hybrid transmission solutions combining MMC and diode rectifier units (DRU), such as DRU-MMC parallel connection hybrid rectifier transmission (PCDRU-MMC) and DRU-MMC series connection hybrid rectifier transmission (SCDRU-MMC), have been proposed to overcome these limitations. This paper presents a total lifecycle cost (TLCC) model for offshore wind power transmission schemes and performs an economic analysis of four transmission schemes: MMC-HVDC, FFTS, PCDRU-MMC, and SCDRU-MMC, under large-capacity and long-distance scenarios. Sensitivity analyses are also conducted to explore the impact of offshore distance, installed capacity, electricity prices, and operating hours on the economic performance of each scheme. Results indicate that hybrid transmission schemes, particularly SCDRU-MMC, offer significant cost advantages, especially in offshore wind power transmission applications with long distances and high capacities.